324139 research outputs found
Sort by
Cement‐SnSe Thermoelectric Devices With High Seebeck Coefficients
Get PDFIn this work, we present a cost‐effective, scalable approach for fabricating thermoelectric (TE) generators using p‐type tin selenide (SnSe) bonded in a cement matrix via a slurry mold casting technique. Traditional methods for manufacturing SnSe‐based TE materials are energy‐intensive and economically unfeasible. By contrast, our approach employs common Portland cement as a binder, offering a viable alternative that reduces processing time, complexity, and cost. Ball‐milled SnSe is mixed with varying concentrations of cement and cast into molds for samples, resulting in dimensions of 1.5 × 1.5 × 0.75 cm3. The best‐performing formulations are 0.2 wt.% cement, which exhibited a power factor of 77 µW m−1·K−2 at 800 K and the 0.3 wt.% cement sample, which has a peak ZT of 0.3 at 850 K, the highest ZT of any cement containing TE to date. A proof‐of‐concept thermoelectric generator (TEG) comprising six legs of SnSe‐cement composite demonstrated a peak power output of ∼73 µW at 850 K. Furthermore, calculations show that using the cement‐bonded SnSe to harvest industrial waste heat in a steel‐making environment can yield a potential 1521.3 W m−2 of electrical energy
Measuring the Impact of the Substitution of Innovator Biologics With Biosimilars on Uptake and Costs Among Ontario Public Drug Benefit Recipients
Get PDFIn Ontario, biologics have historically represented a small proportion of public drug claims but a large proportion of spending. Biosimilars, lower cost alternatives to biologics, offer a potential solution to the rising spending on biologics. From March 2023 to January 2024, the Ontario Ministry of Health required public drug program beneficiaries on eight innovator biologics to transition to biosimilars. Clinicians were reimbursed for supporting patients who transitioned. To evaluate the impact of this biosimilar switch policy, we conducted a repeated cross‐sectional study using administrative data from April 2019 to June 2024. For the biologics (innovator and biosimilar) included in the policy, we reported the biosimilar market share, public drug program spending, and clinician support fees. We used interrupted time series analyses to evaluate the policy’s impact, and forecasting to estimate drug cost savings. From March 2023 to June 2024, the percentage of affected individuals on biosimilars increased from 21.7% to 96.5%. Drug cost savings were 46.6 million in Year 1 (April 2023 to March 2024) and 3.4 million across the study period. Ontario’s biosimilar policy achieved high biosimilar uptake and substantial cost savings. Future research should examine the impact of this policy on clinical outcomes to assess its broader implications for patient care and long‐term sustainability
The effect of iron and aluminum substitution on the physical properties of bridgmanite in Earth’s mantle
Get PDFUsing a combination of in situ high-pressure X-ray diffraction (XRD), density functional theory (DFT) calculations, and thermodynamic modeling, this work explores the influence of Fe and Al substitution on the elastic and thermodynamic properties of bridgmanite, a key mineral in the Earth’s lower mantle. The results indicate that Fe and Al substitutions significantly affect bridgmanite’s compressibility and stiffness. DFT calculations show that increasing Fe and Al content leads to a decrease in bulk modulus (K0) under ambient conditions, suggesting a more compressible lattice. However, high-temperature calculations reveal that the softening effect diminishes at elevated temperatures, with the (Mg0.75,Fe0.25)(Si0.75,Al0.25)O3 (FeAl25) composition becoming stiffer than the other studied compositions at temperatures above 1000 K. Experimental XRD data on sintered polycrystalline bridgmanite, in contrast, suggest an increase in K0 with higher Fe and Al content at static conditions, possibly due to extrinsic factors such as sample heterogeneity and grain size. Thermodynamic modeling using Perple X predicts that increasing Fe-Al content stabilizes bridgmanite over a broader range of pressure-temperature conditions, particularly in deeper mantle regions. The modeling also suggests that Fe-Al substitutions could alter seismic velocities and Vp/Vs ratios, contributing to seismic anomalies such as those observed in Large Low Shear Velocity Provinces (LLSVPs) and Ultra-Low Velocity Zones (ULVZs)
On the Assessment and Rationalization of Heterogeneous Nucleation in Investment Cast Superalloys
Get PDFLiquid metal/ceramic reactions are studied using an experimental arrangement reliant on differential scanning calorimetry. The undercooling needed to stimulate solidification is shown to depend strongly not only upon the chemistry of the ceramic but also the oxygen partial pressure. Ceramics based upon Y2O3 and related compounds are emphasized. Characterization using electron microscopy of the interfacial reaction products is used to rationalize the reaction pathways. Our results shed light on the importance of the ceramic mould chemistry in promoting nucleation in these systems. This insight carries significant implications for practical applications, including (i) evaluating zircon sources and impurity effects; (ii) developing new mould formulation less prone to secondary grain nucleation in casting regions isolated from the advancing solidification front; and (iii) identification of grain refiners tailored for equiaxed solidification in superalloy castings
Data Resource Profile: prostate cancer data from Clinical Practice Research Datalink linked hospital records, mortality data and cancer registry standardised to the Observational Medical Outcomes Partnership common data model (CPRD-PCa-OMOP)
Get PDFExploring the potential for ultra-relativistic jets in Scorpius X-1 with low angular resolution radio observations
Get PDFScorpius X-1 (Sco X-1) is a neutron star X-ray binary in which the neutron star is accreting rapidly from a low-mass stellar companion. At radio frequencies, Sco X-1 is highly luminous and has been observed to have jet ejecta moving at mildly relativistic velocities away from a radio core, which corresponds to the binary position. In this letter, we present new radio observations of Sco X-1 taken with the Karl G. Jansky Very Large Array. Using a fast imaging method, we find that the 10 and 15 GHz data show a number of flares. We interpret these flares as the possible launching of fast jets (), previously observed in Sco X-1 and called ultra-relativistic flows, and their interaction with slower moving jet ejecta. Using the period between successive flares, we find that it is possible for the fast jets to remain undetected, as a result of the fast jet velocity being sufficiently high to cause the jet emission to be beamed in the direction of the motion and out of our line of sight. Our findings demonstrate that the ultra-relativistic flows could be explained by the presence of fast jets in the Sco X-1 system
First constraints from marked angular power spectra with Subaru Hyper Suprime-Cam Survey First-Year Data
Get PDFWe present the first application of marked power spectra to weak lensing data, using maps from the Subaru Hyper Suprime-Cam Year 1 (HSC-Y1) survey. Marked convergence fields, constructed by weighting the convergence field with non-linear functions of its smoothed version, are designed to encode higher-order information while remaining computationally tractable. Using simulations tailored to the HSC-Y1 data, we test three mark functions that up- or down-weight different density environments. Our results show that combining multiple types of marked auto and cross-spectra improves constraints on the clustering amplitude parameter by 43 per cent compared to standard two-point power spectra. When applied to the HSC-Y1 data, this translates into a constraint on . We assess the sensitivity of the marked power spectra to systematics, including baryonic effects, intrinsic alignment, photometric redshifts, and multiplicative shear bias. We note that some of the additional information introduced by the marked field originates from scales smaller than the scale cut, and is partly Gaussian in nature. This does not invalidate our systematic tests. These results demonstrate the promise of marked statistics as a practical and powerful tool for extracting non-Gaussian information from weak lensing surveys
Investigating the dynamic roles of educators: a research-driven exploration of teachers designing technology tools for enhanced classroom experiences in Pakistani public schools
Get PDFEducational innovations, especially digital learning technologies, have often been imposed on teachers to integrate into their teaching practices without accounting for their individual experiences and preferences in designing and implementing these innovations. In educational research, one of the methodologies employed to centre teachers’ contextual insights and challenges is the participatory design approach that engages teachers as designers of learning innovations, collaborating with researchers and technological designers. Despite the benefits of participatory research with teachers documented in the literature, its application in developing countries, such as Pakistan, with strained and underfunded public education systems is severely underexplored. To investigate the applicability of this approach in Pakistan, this qualitative study explores the engagement of sixteen public school teachers from four public schools in Islamabad, the capital city, in participatory design workshops. In the study’s first phase, teachers discussed their daily teaching challenges, shared their insights on practitioner-led educational research in Pakistan and examined the usefulness of existing learning technologies. The understanding obtained from this first phase informed the second phase, where the teachers collaboratively redesigned their preferred digital innovations in design workshops, adding specific features to alleviate their issues and evaluating their efficacy in under-resourced public schools.The study’s findings highlight that teachers feel marginalised by the country’s education system and have limited agency to influence institutional practices and government policies as their perspectives are neglected in educational research, the design of digital tools, and the implementation of digital pilot programs. However, their reflections on participating in design workshops suggest they experience empowerment and professional development while collaboratively designing innovative tools and discussing strategies to minimise their persistent classroom challenges. Moreover, such workshops motivate teachers to seek local opportunities to lead educational research and foster a more optimistic perspective on their professional roles. Thus, the findings from the study’s early-stage participatory design process promote involving teachers in longitudinal participatory educational research in Pakistan to advance education technology scholarship and enable continuous teacher professional development by developing their research and design skills
Melanopsin Stimulation Modulates Blackness Induction
Get PDFA central field will become darker with increasing intensity of a surrounding annulus until it appears uniformly black. We investigated the relation between blackness induction of a central field and the stimulation of melanopsin cells in a surrounding field. Silent substitution was used to selectively modulate melanopsin cells while the tristimulus values were kept constant (melanopic/photopic ratio = 0.51–1.21). Eight participants judged the perceived blackness of the center field using a pairwise comparison method for all visual stimulus combinations. Stimuli were presented monocularly for 0.5 or 5 s with 2‐s inter‐stimulus intervals. Statistical analysis was performed using Scheffé's pairwise comparison method (Nakaya variation). The results showed that perceived blackness of the center decreased significantly under the 5‐s presentation condition with increasing stimulation of melanopsin cells in the surround, although perceived blackness of the center increased with increasing luminance in the surround. In contrast, under the 0.5‐s presentation condition, no significant difference in perceived blackness of the center with stimulus intensity to melanopsin cells was found. These results demonstrate that the stimulation of melanopsin cells of the surround modulates blackness induction of the center at longer stimulus durations
Novel application of a conservation detection dog to recover wildlife telemetry equipment
Get PDFBackground: Wildlife tracking technologies are increasingly used to study animal behaviour, inform conservation management, and answer fundamental questions in ecology. However, a drawback to wildlife telemetry is that equipment is expensive and can be difficult to retrieve when lost in the field, leading to loss of data and inefficient use of project resources. As a potential solution, we began training dogs to search for and locate GPS tracking devices by scent. This approach targets the odour of the device itself, rather than the animal carrying the device. Here, we report on the training, deployment and evaluation of a wildlife telemetry detection dog. Results: During field deployments, the detection dog successfully recovered $11,200 AUD worth of lost GPS devices over a 16-month period. In a controlled field evaluation, the detection dog located 100% of targets compared to 43% by the human-only search. The detection dog was significantly faster, with an average search time of 6.4 min (± 1.5 SE, n = 17) compared to 43.9 min (± 4.9 SE, n = 14) for human-only searches. Combining detection rate and search speed, the detection dog was 16 times more efficient. Conclusions: This is the first reported use of a detection dog to recover wildlife telemetry devices. The detection dog significantly improved device recovery efficiency, with benefits including reduced project costs and improved data completeness. This approach has broad applicability across diverse species and contexts, particularly when visual searching is inadequate such as in dense vegetation or when equipment is buried underground. This novel method offers a practical solution to equipment recovery challenges facing wildlife tracking programs worldwide